Section (botany) in the context of "Pinus classification"

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⭐ Core Definition: Section (botany)

In botany, a section (Latin: sectio) is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section; and the rank of series, if present, is below the section. Sections may in turn be divided into subsections.

Sections are typically used to help organise very large genera, which may have hundreds of species. A botanist wanting to distinguish groups of species may prefer to create a taxon at the rank of section or series to avoid making new combinations, i.e. many new binomial names for the species involved.

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👉 Section (botany) in the context of Pinus classification

Pinus, the pines, is a genus of approximately 110–120 extant tree and shrub species. The genus is currently split into two subgenera, subgenus Pinus (hard pines), and subgenus Strobus (soft pines). Each of the subgenera have been further divided into sections and subsections based in the past on morphology, ecology and biogeography, and more recently increasingly from chloroplast DNA sequencing and whole plastid genomic analysis. While the genetic analysis has given robust results at the higher levels, they often give conflicting results lower in the phylogenetic trees, with species allocated to different subsections (and sometimes different sections) by different studies or even within a study. Within subsections, the genetic relationships between species can be even more complex and conflicting; in one study, three samples of the very distinctive and morphologically constant Pinus lambertiana were placed in three different clades of the subsection Strobus, and similar problems with many other species with widespread nonmonophyly.

Several features are used to distinguish the subgenera, sections, and subsections of pines; the number of leaves (needles) per fascicle, whether the fascicle sheaths are deciduous or persistent, the number of fibrovascular bundles per needle (two in Pinus, one in Strobus), the position of the resin ducts in the needles (internal or external), the presence or shape of the seed wings (rudimentary or effective, articulate or adnate), and the position of the umbo (dorsal or terminal) and presence of a prickle on the scales of the seed cones.

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Section (botany) in the context of Rhododendron sect. Tsutsusi

Rhododendron section Tsutsusi (spelled Tsutsuji in some older texts) was a subgenus of the genus Rhododendron, commonly referred to as the evergreen azaleas. In 2005 it was reduced to a section of subgenus Azaleastrum. Containing 80 to 117 species, it includes both deciduous and evergreen types and is distributed in Japan, China and northeastern Asia. They are of high cultural importance to the Japanese. Among the species in this genus lie the largest flowering azaleas.

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Section (botany) in the context of Blueberries

Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Commercial blueberries—both wild (lowbush) and cultivated (highbush)—are all native to North America. The highbush varieties were introduced into Europe during the 1930s.

Blueberries are usually prostrate shrubs that can vary in size from 10 centimeters (4 inches) to 4 meters (13 feet) in height. In the commercial production of blueberries, the species with small, pea-size berries growing on low-level bushes is known as "lowbush blueberries" (synonymous with "wild"), while the species with larger berries growing on taller, cultivated bushes is known as "highbush blueberries". Canada is the leading producer of lowbush blueberries, while the United States produces some 29% of the world's supply of highbush blueberries.

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Section (botany) in the context of Rubus fruticosus

Rubus fruticosus L. is the ambiguous name of a European blackberry species in the genus Rubus (part of the rose family). The name has been interpreted in several ways:

  • The species represented by the type specimen of Rubus fruticosus L., which is also the type specimen of the genus Rubus. This specimen is considered to match the species R. plicatus, in Rubus subgenus Rubus, section Rubus.
  • Various species consistent with Carl Linnaeus' original description of the species, which was based on a mixture of specimens now considered to match Rubus ulmifolius and R. plicatus
  • a species aggregate (group of similar species) Rubus fruticosus agg. (a nomen ambiguum) that includes most (or rarely all) of a group called Rubus subgenus Rubus (or less often: Rubus section Rubus [sensu latissimo] ):
    • in a narrow sense, sometimes separated as the section Glandulosus (alternative name: subsection Hiemales) In this sense the species aggregate does not include the type of the genus Rubus.
    • in a broad sense: (1) (i) sections Glandulosus and Rubus [sensu stricto] (in non-British systems, these two sections are classified together as section Rubus [sensu lato], section Glandulosus being called subsection Hiemales and section Rubus [sensu stricto] being called subsection Rubus) or (ii) "most of" these sections; or (2) sections Glandulosus, Rubus [sensu stricto] and Corylifolii. Section Rubus [sensu stricto] are probably hybrids involving members of section Glandulosus with either R. idaeus or R. allegheniensis. Section Corylifolii are probably hybrids involving members of section Glandulosus with R. caesius.
    • even more broadly, including all the taxa in the subgenus Rubus
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Section (botany) in the context of Solanum

Solanum is a large and diverse genus of flowering plants, which include three food crops of high economic importance: the potato, the tomato and the eggplant (aubergine, brinjal). It is the largest genus in the nightshade family Solanaceae, comprising around 1,500 species. It also contains the so-called horse nettles (unrelated to the genus of true nettles, Urtica), as well as numerous plants cultivated for their ornamental flowers and fruit.

Solanum species show a wide range of growth habits, such as annuals and perennials, vines, subshrubs, shrubs, and small trees. Many formerly independent genera like Lycopersicon (the tomatoes) and Cyphomandra are now included in Solanum as subgenera or sections. Thus, the genus today contains roughly 1,500–2,000 species.

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Section (botany) in the context of Quercus ilex

Quercus ilex, the holly oak, also (ambiguously, as many oaks are evergreen) evergreen oak, is a large evergreen oak native to the Mediterranean region. It is a member of the section Ilex of the genus, with acorns that mature in a single summer.

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Section (botany) in the context of Bryophyllum

Bryophyllum (from the Greek βρῦον/βρύειν bryon/bryein = sprout, φύλλον phyllon = leaf) is a group of plant species of the family Crassulaceae native to Madagascar. It is a section or subgenus within the genus Kalanchoe, and was formerly placed at the level of genus. This section is notable for vegetatively growing small plantlets on the fringes of the leaves; these eventually drop off and root. These plantlets arise from mitosis of meristematic-type tissue in notches in the leaves.

Nowadays, bryophyllums are naturalized in many parts of the tropics and subtropics, and deliberately cultivated for their attractiveness or for their interesting reproduction as a vegetative reproductive plant.

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